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20 November 2008, 14:25 UTCHappy 4th Birthday, AXIS
Here are a few of the oldest screenshots and concept shots of the program
that later became AXIS. They date from November 2004, making AXIS
4 years old this month. read more...
12 November 2008, 2:27 UTCRELEASED: emc 2.2.7
I'm pleased to announce the next release of the emc 2.2 series, emc
2.2.7. This version contains many bugfixes, including many enhancements
and bugfixes for the new "hostmot2" (hm2) family of drivers for the Mesa
PCI and parport cards such as 5i20 and 7i43.
Full announcement: http://article.gmane.org/gmane.linux.distributions.emc.devel/1382
Changes in this release:
- pop up a message when the right kernel isn't running
- halcmd will now show an error message instead of segfaulting when
inadequate locked memory is available
- allow emc2-sim to be built on 8.04
- stepconf: fix "negative SCALE" problem reported by Christopher Purcell
- comp: fix bad C code generated from variable array declarations such as
'variable double output[8];'
- documentation improvments
- axis: "touch off" of rotary axis on metric machine
- hostmot2: Support all the PCI, PC/104-Plus, and EPP "Anything I/O"
boards: 5i20, 5i22, 5i23, 4i65, 4i68, and 7i43. PCI users should
switch from hm2_5i20 to hm2_pci driver.
- hostmot2 changes: Config changes required! pwmgen.scale now works as
advertised; stepgen timing params are "u32 ns" instead of "float
seconds"; and stepgens now have a .enable pin which needs setting.
- hostmot2 feature additions: Added PDM mode for pwmgen; PWM and PDM
frequency are now settable by the user; implemented stepgen maxaccel
and maxvel; support open-drain GPIOs; all GPIOs now have some
representation in HAL (though the ones used by module instances are
restricted); encoder improvements.
- Lots of hostmot2 bug fixes, mostly with pwmgen and stepgen. Thanks to
all the brave testers!
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10 November 2008, 13:48 UTCDouble Precision checked in
(earlier posts: part 1, part 2, part 3)
After talking to John Kasunich about it on IRC, we agreed that the patch was
suitable to be checked in. That patch was followed by two rounds of changes
to drivers where "float"-type variables were used for temporaries or locals.
The testsuite still passes, and no other problems have turned up yet.
Hopefully, this major (if subtle) improvement will wind up in 2.3.
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3 November 2008, 2:49 UTCStill more doubles The test I wrote earlier to run inside hal has one main flaw: the
fatal window (if there is one) will only be seen when the fast thread
interrupts the slow thread during the correct processor cycle; this won't
necessarily happen very often!
So I crafted a threaded userspace program that "busy loops", one thread
doing the 'update' and one thread doing the 'check'. On a dual-core
machine, the correct program will run for as long as I let it. If I
change the compiler flags (e.g., to -mtune=i386) or change the program
to not 8-byte-align the shared variable, I quickly see failures---typically,
within a few seconds. read more...
1 November 2008, 14:21 UTCFurther double work I updated scope_rt to use the "double read and compare" method to
reliably sample doubles. I also created a test component designed to detect
half-stored doubles. Update: I also tested on a 64-bit system.
And things look good so far! read more...
31 October 2008, 21:04 UTCDoubles in HAL?
 Result of 'ddt' of sin(t)+10000
showing the difference that 'double' precision makes
I've talked before about doubles in hal--why we'd
like to have them, and why we don't have them now.
After reading the source to current versions of gcc, and thinking about
the motivations for writing "two movl" sequences to load or store doubles
on x86, I have a high level of confidence that the guarantee on Pentiums
for 8-byte-aligned doubles is enough to give the same atomicity requirements
for 'double' pins as other types, as long as a few assumptions are made
about the compiler. I've produced a patch and show one way in which this
is a big improvement. read more...
30 October 2008, 20:02 UTCEMC2 on Ubuntu: Stick with Hardy Heron
The precompiled versions of emc2 are only compatible with Ubuntu 8.04 and
Ubuntu 6.06. Upgrading to 8.10 will remove the emc packages and make your
system unable to run emc.
Why aren't there packages for Ubuntu 8.10?
We have chosen to use 8.04 because it's a "long term support" (LTS) release. If
you use it, you can be sure of support and security fixes from the Ubuntu team
for 3-5 years. However, we would be happy to accept and host packages for other
versions if a user/developer of emc2 wishes to contribute them.
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30 October 2008, 16:33 UTCEMC2 carves pumpkins
 The Lumenlabs CNC-milled Pumpkin
Among the many uses of emc2: carving pumpkins! Happy Halloween.
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20 September 2008, 21:58 UTCNew screws and nuts for the zenbot At Chris's suggestion, I bought new acme leadscrews and dumpstercnc anti-backlash leadnuts. This was to
replace the old triangular leadscrews and brass nuts, which measured huge
backlash, .010" or more on X. This was due at least in part to wear on the
nuts: fine brass dust was visible around the leadnuts after I ran a stall test
of 1000 inches or so at 1.5ips; I had earlier measured the backlash as only
about .005". read more...
14 September 2008, 2:10 UTCCopper-clad dragon
I started with a piece of dragon art I found online in gif format, converted to
vector with inkscape, played a tiny bit with paths, and then converted to gcode
with skencil. (an update of my skencil gcode converter is way overdue as I
discovered several important problems there -- hopefully I get around to
posting that soon) read more...
26 August 2008, 1:46 UTCZenbot: more success milling circuit boards 16 August 2008, 22:53 UTCZenbot with Wolfgang Engineering "TB" Spindle 10 August 2008, 18:07 UTCRELEASE: emc 2.2.6 6 August 2008, 1:29 UTCZenbot gets home switches 17 July 2008, 3:15 UTCZenbot Tool Length Sensor 4 July 2008, 16:49 UTCZenbot Lives 5 June 2008, 14:47 UTCaxis-dropbox: Automatically open new or modified gcode files in axis 12 May 2008, 14:56 UTCExperimental Ubuntu 8.04 + EMC2 Live CD 12 May 2008, 14:51 UTCRelease: EMC 2.2.5 16 March 2008, 21:36 UTCRelease: EMC 2.2.4 28 January 2008, 3:42 UTCRelease: EMC 2.2.3 16 January 2008, 15:47 UTCGenerating HAL files from Eagle schematics 25 December 2007, 14:51 UTCImproved Analog & Digital Interface with Arduino 24 December 2007, 19:46 UTCAnalog inputs with Arduino and EMC 21 December 2007, 14:54 UTCEMC runs a real 5-axis machine 18 December 2007, 13:42 UTCEMC 2.2.2 released 26 November 2007, 16:30 UTC5-axis machining with emc 8 November 2007, 16:59 UTCAnd the first new features start appearing in CVS... 8 November 2007, 16:40 UTCEMC 2.2.1 released 5 November 2007, 18:39 UTCEMC 2.2 released
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